Variable-pressure bed or mattress



Aug. 5, 1930. J, D, HA T 1,772,310

VARIABLE PRESSURE BED OR MATTRESS I Filed Dec. 16 1926 2 Shepts-Sheet l3" 35 I B 7 Jada/12.17am, L U .7 Q [3 3 f ma. 6% M,

Aug. 5, 1930. .1. D. HART VARIABLE PRESSURE BED OR MATTRESS Fi led Dec.16 1926 2 Sheets-Sheet. 2

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H II Patented 'Aug. 5, '1930 l UNITED STATES JULIAN n. HART, orBALTIMORE, MARYLAND VARIABLE-PRESSURE BED OR MATTRESS Application filedDecember 16, 1926. Serial No. 155,229.

In the care or treatment, in homes, hospitals and various institutions,of sick or injured patients who are confined permanently or for lengthyperiods in bed and who are able to turn themselves only rarely, and inthe care or treatment of very sick, severely injured or paralyzedpatients who are unable to turn themselves at all, it is very diflicultto prevent the formation of bed-sores. These bed-sores l are caused byunduly long continued pressures upon the skin, generally mostprominently displayed at the points of the bony protuberances, wherebythe supply of blood with its tissue renewing substances tothe body areassubjected to pressure is materially reduced or inhibited, with theresult of the breaking down of the tissues and the development ofso-called bed-sores. It is frequently impossible for nurses or otherattendants because of other multifarious duties to be able'to give timeto turn the patients as often as is necessary with the use of presentequipment to pre vent such sores from being formed. There are alsocertain cases in which it is undesirable to turn the patient at toofrequent intervals, making it all the more difficult to preventbedsores. Heretofore various efforts have been made to preventbed-sores,the most common being that of placing the patients on pneumaticmattresses by means of which the pressure is more widely distributedinstead of being most marked under the bony prominences. In certaincases, notably those of patients with complete paralysis, the patientsare frequently placed in tubs containing warm water which must be keptat a constant tempera- Y ture, with some means provided for the disposalof waste water and constant supply of warm water and some means forsupporting the patient in the tub, presenting difficulties whichrequireminute attention.

' The primary object of my invention is to overcome'these difitlc'ultiesand to provide a bed which allows the patientto be comfortablysupported, and which provides for the shifting of the sustainingpressuresfrom dif-.

ferent portions or areas of the skin to other portions or areas asfrequently as necessary, and which will operate automatically for 5pressure shifting actionswith aminlmum amountof care or service on thepart of the attendants and consequently with greater ease and comfort tothe patient and decreased burden on the partof the attendants in thecare of patients entrusted to them.

A further object of my invention is to provide a bed of inflatablemattress type which is suitably constructed or divided up into pressuresustaining fields, zones or areas,combined with inflating and deflatingmeans for relatively varying the pressures of such fields, zones orareas at predetermined time periods, such means operating automaticallyto vary the pressures at such intervals as may be required in thetreatment of any particular case, without particular care or attentionon the part of the attendants.

A still further object of the invention is to provide a simple, reliableand eflicient construction of bed or mattress of the type described, anda simple, reliable and eificient type of automatic means for varying thepressures and which is regulable at will for controlling the degree ofpressure and the time periods of the pressure shifting actions.

A still further object of the invention is to provide automatic meansfor supplying air or other fluid under pressure, and varying thepressures thereof, which ensures a certainty of action and reliabilityagainst either over inflation or disruption of anyof the component partsof the bed.

A still further object of the invention is to provide a bed of thecharacter described which, through its pressure varying actions, willalso operate to stimulate and keep'the skin in a healthy condition. I

A still further object of the invention is to provide for use inconjunction with such bed novel, reliable and efiicient means forturning a patient from one side to the other of the bed whenever desiredor required.

With these and other objects in View, the invention consists of thefeatures of construction, combination and arrangement of parts,

hereinafterfully described and claimed, reference being had to theaccompanyingdrawings, in wh1ch:-

Figure 1 is a top plan view,.show1n% a1.

portion of the cover broken away, of a ployed.

Figures 5 and 6 are end elevations of the.

I bed, illustrating the use of the means for turning a patient.

Figure 7 is a side elevation looking toward the right in Figure 5 ortoward the left in Figure 6.

Figure 8 is a view in elevation showing one type of automatic fluidsupply and exhaust mechanism which may be employed for pressure varyingactions, the automatic governing valve thereof appearing inthe positionwhich it occupies for supplying fluid pressure to one set of cells andreducing the pressure in another set of cells.

Fi ure 9 is a view similar to Figure. 8, but

showing the valve insection and in its reverse position.

Figure 10 is a fragmentary plan view illustrating one of many possiblemodifications in the construction of the bed or mattress which maiy beemployed.

n the constructional example shown in Figures 1 to.9, inclusive, of thedrawings, 1

. designates a bed or mattress embodying one form of the invention, and2 a bedstead or supporting frame for the mattress which may be of anyconstruction suitable for the purpose.

The body of the bed or mattress 1 is composed of a lurality of bags orcells 3 preferabl of rub r or other suitable elastic materia although anon-elastic material or a semi-elastic material or suitable combinationof elastic or non-elastic materials may be used. An suitable number ofthese bags or cells may eemployed, according to the size of the mattressand the number of pressure fields, zones or areas in whichit is to be divided. In the present instance, the mattress is shown as ma e up offourteen of such cells, each of substantially oblong rectangular formand of a length corresponding to the width of the mattress, the cellsbeing arranged in parallel relation to each other and extendinlongitudinally in-a direction transversely o' the mattress. Preferablythe cells. are enclosed within an outer casing oncoverin of canvas,ducking, 'or other suitable fa me which casing or coverin may be dividedby partitions 5 into suitable pockets or compartments receiving andholding the cells slightly separated and preventing them from' becomingdisplaced or shifting relatively to eachother.

The cells may be of rectangular, oblong rectangular, circular,elliptical or any other suitable form in cross-section, and their topwalls may be normally flat or convexly curved or of other suitable formand adapted to assume any preferred supporting form when inflated. Inthe present instance I have shown the cells so formed or constructedthat the top wall surface of each cell will, when the cell is expanded,assume a transversely convex form, and, when the cell is more orless-deflated will assume a concave form, so

that by a proper arrangement of the cells, to

, control inflation of certain cells and deflation of others, the upperor. supporting surfaces of a certain number of the cells may beprojected and the upper or supporting, surfaces of the remaining cellsretracted with respect to a certain mean level whereby the supportingzones or areas on which the patient rests may be varied at will. -Withthis construction when certain cells are inflated and others relativelydeflated a bed surface of wavy, undulating or corrugated form willbepresented, the elevated portions .or crests of which will serve as thesole or main supporting areas, and the valleys or depressed portions ofwhich will serve as non-supporting or minor supporting areas. Therelative elevations of the elevated and depressed portions of the bedmay, therefore, be such as to provide a more or less continuoussupporting surface, the supporting pressures of which on differentportions of the body of the patient contacting therewith will vary, thusgiving the desired pressure relief actions, which can be shiftedrelatively to different portions of the body of the patient by makingthose areas which have been high areas low areas, and vice versa. On theother hand, the degrees to which the different cells or areas areinflated, or relatively inflated and deflated, as well as the form ofthe cells, may be such that the more highly inflated areas mayconstitute the entire supporting surface in use at any time to sustainthe patient, while the deflated or relatively inflated cells or areaswill be wholly devoid of supporting action, i. e., lie out of contactwith the body of the patient. I, therefore, do not limit my invention toany particular form or shape of the cell bodies or their top walls, orto any particular. cell at.- rangement for securing or mode of seriallyinflating the cells in order to secure shifting pressure applying(supporting) and pressure relief surfaces, except when particularlyspecified in the appended claims. It isalso to be understood that by theuse of the word deflating I mean either total deflation or partialdeflation of one cell or set of cells with respect to another cell orset of cells, as either mode may be employed dependent upon theconstruction of the bed or mattress, and as under many conditions totaldeflation would be uneconomical in the use of fluid ternation with eachother. The cells of series 3 are all connected with a fluid supply andexhaust pipe 6v and the cells of series 3" are 'all connected with afluid supply and exhaust pipe 7, so that the cells of each series may besimultaneously inflated or deflated, and

so that the cells of'one series may be inflated and thecells of theother series simultaneously deflated- By inflating the cells of oneseries and simultaneously wholly or more or less deflating the cells ofthe other series,

alternate cells of the mattress, from head to foot thereof, will beinflated and deflated,

with the result of projecting or raising the upper surfaces of one setof cells and lowering or retracting the upper surfaces of the other setof cells with respect to a mean hOI'lzontal plane, whereby a bed ormattress having a supporting surface .of undulating contour willbepresented, as shown in Figures 2 and 3, The top cells of the inflatedor expanded cells will accordingly form the pres sure zones or areas, orpoints of support for the patient, while the top walls of the deflatedor relatively deflated cells will be located atsuch a lower level as tolie out of contact with the patient, so that a broken instead of acontinuous surface for the support of the patient will be produced. Thecells may be so dimensioned and shaped that the tops of the inflated anddeflated cells will pro vide a regular or irregular undulatingsupporting surface, 1. e., of curved or non-curved contour, the crestsof WlllCll, represented by the tops of the inflated cells, will lie indirectcontact'with portions of the body of the pa tient and besufliciently close together to form a comfortable elastic support, whilethe tops of the deflatedcells will lie below and rest lightly against orhe out of contact with the body of the patient and thus relieve thepatientpartly or wholly from pressure along those areas of the mattressconstituted by the deflated cells. Under the weight of the patientresting upon the tops of the inflated cells, such portions of theinflated cells tend to flatten out and overlap to an extent they tops ofthe deflated cells, so that the extent of the supporting area will beincreased to a degree proportionate to the flattening extent, which maybe governed by the pressure to'which the inflated cells are inflated,without, however, in such action bringing the tops of the inflated anddeflated cells into a common plane. Asa result, it will be apparent thatthe concaved surfaces of the deflated cells may also form supports forcertain portions of the body which are not directly sustained by theinflated cells, so that such portions of the body may rest very lightlyupon or be wholly out of contact with adjacent deflated cells. Thearrangement of the cells in sets or series adapts the respective sets orseries of cells to be alternately inflated and deflated at suchintervals as may be desired, so that the undulating contour of the topsurface of the mattress may be varied. Figure 2, for example, shows anundulating contour presented when the cells 3 are inflated and the cells3 are deflated, while Figure 3 shows a different undulating contournecessary or desirable in general or particular cases in orderto preventthe format-ion of bed-sores.

Figures 8 and 9 I have shown a type of fluid pressure supply and controlmechanism for inflating and deflating the cells. This mechanism is ofautomatic type and operable to alternately inflateand deflate the setsor series of cells 3* and 3 at periods desired.

Themechanism comprises a pump, compressor or other suitable source offluid pressure supply 8 with which connects a fluid pressure supply pipe9 communicating with a governmg valve casing 10 containing anoscillatory governingvalve 11. The casing 10 is provided with'a pair ofinlet ports 12 and 13 for communication with the pipe 9, a pair of feedports 14 and 15 communicating with feed pipes 16 and 17 and a pair ofpressure relief or exhaust ports 18 and 19, while the valve 11 isprovided with a feed duct or pas sage 20 and a pair of exhaust ducts orpassages21 and 22. The feed pipes 16 and 17 are suitably connected inpractice with the ends 6" and 7 of the pipes 6 and 7 and are designed byreverse oscillations of'the valve to be alternately connectedby thevalve feed port 20 with the proper feed opening 12 or phere from theother set. of cells for deflating the same to any predetermined extent.In practice, the pipe 9, instead of being directly connected with a pump.or compressor 8, may communicate with a receiver or reservoir or withmain supply pipes of a fluid pressure system designed to supply fluidpressure to any number of beds at a time. In practice also, the fluidsupplied under pressure may be air, water, oil or any other suitablefluid, and this fluid as supplied to the pipe 9 may have an initialpressure of, say, 50 pounds per square inch. For the purpose of reducingand controlling the flow of this pressure to the valve and parts of themattress, there is provided in the pipe 9 a reducing, regulating and cutoifvalve 23. Also for controlling the exhaust of fluid from the cells ondeflation, exhaust pipes 24 and 25 connect with the ports 18 and 19 andare provided with valves 26 and 27 acting as retardin valves, wherebythe rate of exhaust of flui from a set of cells andthe degree ofdeflation of such cells may be regulated and controlled as desired.

Figure 9 shows the valve in section and the position of the rotary valvemember 11 for connecting the pipes 7 and 17 through feed port 12 andpassage with the set of 1 cells 3 for inflating such cells, at whichtime duct 22 is in blank position but-duct 21 connects pipes 6 and 16through ports 14 and 18 with pipe 24 leading to the atmosphere fortheexhaust of fluid pressure to any desired extent from the cells 3 at adetermined rate and within a certain period dependent upon the timeperiods of movements of the valve 26. .The valve 11 is movable to areverse position .for connecting pipes 6 and 16 through ports 13 and 14and duct 20 with the pipe 9 for supplying fluid pressure to intionedflate the cells 3", in which position of the valve duct 21 is moved to ablank position while duct 23 is brought to a position to connect pipes 7and 17 through ducts 15, 22 and 19 with the. exhaust pipe 25 for theexhaust of fluid pressure from the cells 3" to deflate the same more orless in a certain time period de dent upon the retarding position of vve 27. Thus it will be understood that the valve 11 in oscillating inopposite directions will alternately bring the aforemenports, ducts andpi into coaction to success vely and alternate y inflate one set ofcells 35 and deflate the other set of cells 3",

' and vice versa, at predetermined time periods which may be governed bythe factors hereinafter described. V

Extending from valve 11 through one side of the casing is a stub shaftor axle 28 on which is pivotally mounted for swinging movements with andindependently of the valve a valve actuating lever 29. This lever.

29 is coupled by links 30 to the rods 31 and 32 of pistons operating incylinders 33 and 34, said cylinders being connected by combined feed andexhaustipes 35 and 36 with the pipes 16 and 17, so at when fluidpressure is supplied through either pipe 16 or 17 for inflation of themattress cells connected therewith fluid pressure will also be suppliedto the cylinder communicating therewith. Thus when the valve 11 isarranged in the position shown in Figure 9 to supply air to pipe 17 andcells 3", fluid pressure will also be supplied through pipe 36 to thecylinder 34 to move the piston therein on its working motion. In thisposition of the valve shown in Figure 9, air exhausting through the pipe16 from cells 3 and controlled in its discharge by the valve 26 willgovern the discharge of fluid from the working end of cylinder 33, inwhich the piston will be on its return travel during the working travelof the piston in cylinder 34. 'lVhen the valve 11 is adjusted to itsreverse position from that shown in Figure 9, so as to connect pipe 16with the .feed pipe 9 and connect pipe 17 with the exhaust pipe 25, forinflation of the cells 3 and deflation of the cells 3*, respectively,pressure will be supplied to the cylinder 33 to move the piston thereinon its working stroke while simultaneously the fluid may exhaust'frombehind the piston in cylinder 34 during its return stroke through pipe36 and discharge with the air discharging through pipe 16 and pipe 25,governed in its discharging actionby the retarding valve 27 so that onreverse oscillatory motions of the valve 11 the pistons in the cylinders33 and 34 will be successively and alternately operated for swing ingthe valve actuating lever 29in opposite directions.

and 38 projecting from one face of the valve 11 outwardly through anarcuate slot 39 in one face of the valve casing, and in which slot thestuds travel in the oscillatory movements of the valve. its pivoted endbetween these studs, which The lever 29 lies above 4 The lever 29 isadapted for engagement on its reverse motions with studs or tap'pets 37are spaced so as to be engaged by the lever 29 at certain points in itsopposite working travels.- The purpose of the pistons in the cylinders33 and 34, operating under working pressure from the pressure supplysystem, is

to shift the lever in one direction or the other for a portion at leastof its working action, a spring 40 or other auxiliary power device beingprovided to assist in completing or for completing the remainder of eachworking motion of the lever. As shown in the present may be varied. Thespring is normally distended under tension and exerts its leastcontractile' force when the lever 29 is moved to -n Ju a full valveadjusting position in opposite directions and exerts its maximumcontractile force'for a lever throw action upon the movement of thelever in either direction beyond aperpendicularor dead center position.

Figure 8 shows the position of the lever 29 whenthe valve 11 is adjustedto the opposite position from that shown in Figure 9, or to the positionin which valve 11 connects pipe 16 with pipe 9 for inflating the cells3? and pipe 17 with exhaust pipe 25 for deflating cells 3", in whichposition of lever 29 said lever has engaged stud 37 and through theworking action of the piston in cylinder '34 and that of the spring 40,on its movement to the left beyond a perpendicular position,

has through its working pressure on the stud 37 shifted the valve to theopposite position from that shown in Figure 9. -When the valve is soshifted as shown by Figure 8, stud 38 occupies a position a little tothe right or alittle ahead of the valve lever 29 when swung back to aperpendicular position for the purpose of shifting the valve from theposition shown in Figure 8 to that shown in Figure 9, during whichmovementof the lever 29 from the position shown in Figure 8 to aposit-ion in which it is brought into contact with stud 38 the levertravels idly between the studs 37 and 38 and leaves the valve immovableduring such time period of travel and before it engages the stud 38 jand begins to shift the valve shown in Figure 9. During this period ofmovement of lever 29 between studs37 and 38 the valve 11 remains inposition to supply fluid pressure to the cells 3 to inflate them andhold them inflated and to allow the pressure to exhaust from cells 3 todeflate them tothe predetermined extent allowed by the retarding valve27, thus maintaining the pressure conditions and undulating form of themattress shown,

for example, in Figure 2. During this period of idle travel of the lever29, and while it is being urged forward for engagement with stud 38against a certain degree of resistance of spring 40 by the action of thepiston in cylinder 33, the spring is elongated, and its tensionincreased,so'that upon the passage of the lever 29 to the right beyondcenter and on its engagement with stud 38, the'spring,

supplementin the final force of motion of .piston in cyllnder 33,quickly swings the lever 29 to the reverse position shown in dottedlines in Figure 9, thus shifting the valve to the position shown inFigure 9 to reverse the cell inflating and deflating actions. Thisoperation of the valve 11 by lever 29 shifts the stud 38 to the righthand end of slot 39 and brings the stud 37 to a position just to theleft of the center of the slot, so that on the ensuing reverse movementof lever 29 to shift the valve from the posit-ion shown in Figure 9 backto the position shown in Figure 8 the lever 29 will travel idly overstud 38 to stud 37 before beginning its valve reversing action and thespring 40 will shift from the right to the left hand side of the centerof the valve and assist the piston, in cylinder 34 to quickly shift thelever 29-to the left beyond center whereby it is returned to theposition shown in Figure 9 to adjust the valve for inflating cells 3 anddeflating cells 3 It will be observed, therefore, that when the valve isin either working position to connect either set of .cells with thesupply pipe 9, the associated cylinder is also in communie cat-ion withthe supply pipe for the flow of fluid pressure to operatethe pistontherein to transmit motion to the lever 29 for a valve reversing actionduring a time period while the valve is stationary and inflating one setof cells and deflating the other set of cells, and that immediately uponthe beginning of a shifting motion of the valve by lever 29 the spring40 comes into play to complete the movement of the valve at or justafter the time of cut off of the supply of fluid pressure to the workingcylinder, avoiding any reliance upon the momentum of the lever to effectits full positive travel and ensuring also a positive lever motion andvalve shift under all working conditions as against any tendency of thelever or valve to stick at or beyond a dead center position of thelever. Thus through a certain time period while the lever and valve aretraveling in one direction one set of cells will be inflated andmaintained in inflated condition, while the other set of cells will bedeflated and maintained in such condition, this action with respect tothe,

the position shown in Figure 8 to that shown in Figure 9 changes theundulating contour of the supporting surface of the mattress from thatshown in Figure 2 to that shown in Figure 3. The rate of oscillation ofthe valve is dependent on the rate of inflow and exhaust of fluid andthe workin power of the valve actuatin spring 40. T rough the action ofthis spring, the rate of feed and pressure of the fluid supplied throughpipe 9, and the rate of retarding action of the valves 26 and 27, thepressure'in the cells is regulated. As will be readily understood, theworking pressure in the cylinders 33 and 34 must be suflicient' toovercome the resistance of the spring in order to eflfect a shiftingmotion of lever 29 from either of its with the piston in one of thecylinders to complete the throw of the lever and movement of the valveto the reverse position. With the lever in either of its positionsbeyond center, in which it engages stud 37 or stud 38 to start movementof the valve 11 in one directionv or the other, and with a spring offixed power and cylinders and pistons of equal dimensions, the ratioswill be such that the pressures in the sets of cells will be'the same orequalized when the lever is in either of the positions mentioned. Thethrow of the lever in either direction, in which it acts on stud 37 orstud 38, thereafter effects a predetermined degree of change orvariation in the relative pressures of the sets or series of cells. Byvarying the pressure and rate of inflow of the fluid through the pipe 9,the rate of exhaust of the fluid through adjustment of the valves 26 and27 and varying the working pull of the spring by adjustment of theadjustable connection 42, both the working pressure in the cylinders 33and 34 and the rapidity of inflation and deflation of the sets or seriesof cells may be regulated, such adjustments of parts varying therapidity of action of the valve 11. By also varying the pressure andrate of supply of the fluid and its rate of exhaust, the workingpressure in the se s or series of cells may be varied to suit the weightof the patient or other conditions to be met. Instead of employing thetype of valve op erating means defined, I may employ any other suitabletype of valve actuating means, such as of pulley and weight .typeconnected with lever 29, or time-controlled type governed by atime-control mechanism, so that the time periods of operation of thevalve 11 may be varied and made as fast or slow as desired.

In practice, the valves 23, 26 and 27 may be of any suitable type forpressure reducing and retardin actions, such as are employed in airbrake systems and other fluid pressure controlling systems for pressurereducing and retarding or releasing actions. These valves ma also be ofany suitable structure designe for the use of compressed air, water,oil, or any other fluid which may be used, as the inflating'anddeflating medium. It may be found desirable to provide also a safetyvalve 43 of suitable type in each feed pipe 16 and 17, or in othersuitable portions of the pressure supply system for the purpose ofrelieving the mattress cells of excess pressures to prevent undueinflation or disruption of any cells under inflation and to therebyprovide a variable-pressure mattrem which may be operated with safety under all conditions. These valves 43 may be of the automatic safetyrelease type used in airbrake systems or equivalent valves used c influid pressure systems of all kinds for pressure relief actions. Whendesired, the

mattress may be provided with an opening wise in a directionlongitudinally of the bed. 7 Instead of, under these conditions,employ:-

ing cells of full length type extending either transversely orlongitudinally of the bed, I may employ a mattress structure made up orsmall cells 3 and 3, arranged in rows, of a plurality of cells in eachrow, extending either transversely or longitudinally of the .bed. Thecells of each row may be connected with the supply pipes so that all thecells of a common row may be simultanenously inflated and deflatedthroughout a group of rows forming a mattress from side to side or fromend to end of the mattress, or I may, as shown in Figure 10, connect thecells of each row alternately with the pipes 6 and 7, and with the cellsof adjacent rows, so that alternate cells of each row ma and the cellsof adjacent rows inflated and deflated in a staggered manner withrelation to each other. By constructing the mattress in the generalmanner shown in Figure 10, of which many modifications in the sys ternof piping are possible in order to vary the pressure reducing andpressure relief points throughout the mattress, a type of mattress maybe produced having a very large number of inflatable and deflatablefields, zones or areas which may be inflated and deflated so as toobtain wide variations in the points or places of pressure applying orsustaining and pressure reducing actions, as will be readily understood.I, therefore, do not limit the invention to any particular constructionand arrangement of the cells of the mattress, or their pipingconnections for inflating and deflating actions, provided a plurality ofareas may be inflated and a plurality of areas simultanenously deflatedat a time, as obviously the construction of the mattress may be modifiedin such respects to wide degrees invention.

be inflated and deflated In the care or treatment of bed ridden patientsit is'also desirable to provide means whereby the patient may be turnedfrom one side of the bed to the other in a convenient and gentle mannerand to save time and labor,

in this connection, on the part of nurses or other attendants. For thispurpose I provide turning devices whereby the mattress 1 may be raisedand lowered on either side of its longitudinal center, as shown inFigures 5, 6 and 7, thereby adapting the patient to be turned from sideto side of the bed at such time periods as may be found necessary ordesirable without effecting the pressure vary--- ing actions of themattress. The turnin devices consist of inflatable and deflatableliagsor cells and 46 located on opposite sides of the longitudinal center ofthe mattress 1 and between the same and its supporting base of thebedstead 2. Each of these cells is preferably of elastic material and ofa length conforming to the length of the mattress and is of pyramidal ortriangular form or other suitable form in cross-section, each cellhaving one of its sides 47 and preferably both of its ends pla-ited orotherwise constructed or formed to fold, accordion-fashion, to permitthe cell to expand freely to its major dimensions and to collapse in asubstantially flat manner. Pipes 48 are provided for connecting thecells with a source of fluid pressure supply, such as that shown, sothat either cell may be expanded and collapsed at will. When both cellsare collapsed, they lie in a substantially flat condition beneath themattress, so that the mattress throughout will lie in a normalhorizontal plane. By inflating cell 45, the half of the mattress on theleft hand side of its longitudinal center may be elevated to turn thepatient over onto the other side of the mattress which remains in itsnormal horizontal position. Similarly, when cell 45 is deflated, andcell 46 is inflated. the half of the mattress on the right hand side ofits center, as shown in Figure 6, will be elevated to turn the patientin the opposite. direction over upon the right hand side of the mattressremaining in normal horizontal position. By gradually supplying thefluid pressure to or exhausting the same from either cell a Very easyand gentle lowering or raising action may be effected to turn thepatient without causing jolts, jars or other distress to him.In'practice, the control of the fluid pressure supplied to and itsexhaust from the cells may be hand operated or.gov-' erned by automaticmeans in either event with a saving of time and labor to nurses andattendants. It is to bennderstood that this 51-. principle of turningdevice may be emploved in various forms, to suit conditions indifferentcases. The turning devlce, for example, instead of being coextensive 1nlength with the mattress, may. be shorter than the mattress and employedto elevate any certain portion or restricted portion of the body of apatient, that is to say, to raise the body of -the patient at one sidebetween the shoulder and the hip, or below the hip,'or the turnmg devicemay be made in the form of a bd l ster.

' feet. I therefore do not liniit'the invention extending transverselyof the bed soas to raise the head or upper portion of the body of thepatient, or to'raise any portion of the body of the patient between hishead and his in this particular. I By inflating I mean supplying supporting pressure of any degree desired to those cells or subdivision ofcells which are to have a supportin action,and, as'before stated, bydeflating l means a reductionfof pressure to any degree from those cellsnot at the time used or to be used for a supporting action, whichreduction may be of any degree between absolute deflation and a pressurefalling slightly short of full supporting pressure. In practice,those'cells which are deflated for a pressure relieving action may besimply relieved of suflicient pressure to more or less relieve theirsupporting pressures from the patient, as full deflation is unnecessaryand undesirable from the standpoint of economy of use of the pressurefield.

From the foregoing description, taken in connection with the drawings,the construction and mode of operation and. use pf my improved'mattresswill be readil understood, and it will be seen that the inventionprovides amattress of the character and'for the purpose described whichis simple of cona5 struction and adapted to be operated to over-fcomethe objections to prior constructions of beds or mattresses andeffectually obviate and prevent those condit-ipns 'causing the forumtion of bed-sores. By its "use patients, even 7100 when long bed ridden,may be made more' comfortable and kept free from sores brought aboutfrom prolonged pressure upon and lackof blood circulatlon in some-areas.I Incident-1y the mattress alsohas an additional function, that is tosay, the change of pres-j sure from portions to portions of those parts;of the body of the patient lying upon the mat tress causes a gentle buteffective massaging A action whereby the skin is stimulated and a lltcounteracting influence exerted as against the 4 supporting pressuresexerted, serving as a further prevention against the f'ormationofbed-sores; Having thus fully described my invention, I claim 1. Apneumatic mattress having a support-.1

ing surface comprising juxtaposed rows of 2. A pneumatic mattresscomprising 1on"-j! 9- I gitudinal and transverse rows of cells forming abody supporting surface, the cells of the rows being connected in groupsalternating in arrangement with each other in adjacent rows of'cells,and means for automatically and simultaneously inflating all the cellsof one group and deflating all cells of another group and reversing theorder of inflation.

' and deflation of the cell groups on successive inflating and deflatingactions.

3. A pneumatic mattress having a supporting surface comprisinginflatable and deflatable cells connected in groups to form a bodysupporting surface, the cells of the groups being alternated withrelation to each other, a source of fluid under pressure, means forreducing the pressure of the fluid and JULIAN n. HART.

automatic means supplying the fluid under reduced pressure to a certaingroup of cells for simultaneously inflating all the cells thereof whilesimultaneously deflating all the cells of another group, and forreversing the order of inflation and deflation of the groups of cells onsuccessive inflating and deflating actions, and means for relievingexcess pressure in the cells when the fluid pressure exceeds to apredetermined degree the reduced pressure.

4:. A mattress formed of a plurality of inflatable and deflatablesections arranged in groups, the sections of one group alternating inarrangement with the sections of another group to form a continuous bodysupporting surface, and automatic means for simultaneously inflating allof the sections of one group and deflating all of the sections ofanother group, said means acting to inflate and deflate said groups inserial order.

5. A mattress composed of a plurality of inflatable and deflatablecells, arranged in groups, the cells of the groups being alternated andjuxtaposed to provide a substantially continuous body supportingsurface, and automatic means alternately inflating all the cells of onegroup, and simultaneously deflating all the cells ofanother group, and

then deflating the cells of the first-named group and inflating thecells of the secondnamed group.

6. In an article of manufacture, a plurality of juxtaposed inflatableand deflatable cells forming a mattress, a source of fluid pressuresupply, means connecting said supply with said cells, means controllingthe flow of fluid pressure from said source to the cells and thedischarge of fluid pressure from the cells, said means beingautomatically operated to increase the pressure in certain cells anddecrease the pressure in certain other cells and to periodically changethe cells in which the pressure .is so increased or decreased wherebypressure on the body of the person lying on the mattress will beperiodically relieved.

7. In anarticle of manufacture, a plurality

